Wax thread sewing machine with a looper



April 5, 1960 F. E. COLE WAX THREAD SEWING MACHINE WITH A LOOPER 2Sheets-Sheet 1 Original Filed Oct. 16, 1953 Jew/ J Z a/213% 77% 2? VizApril 5, 1960 F. E. COLE WAX THREAD SEWING MACHINE WITH A LOOPEROriginal Filed Oct. 16, 1953 2 Sheets-Sheet 2 lllll lllllllllll I WAXTHREAD SEWING MACHINE WITH A LOOPER Frank E. Cole, Manchester, Mass.,assignor to United Shoe Machinery Corporation, Flemington, N.J., a cor-'poration of New Jersey Original application October 16, 1953, SerialNo. 386,551. lyfigiged and this application August 6, 1958, Serial No.

8 Claims. (Cl. 112-42) The present invention relates to improvements ina wax thread shoe sewing machine with a looper and is herein disclosedin a preferred form as embodied in an inseam sewing machine having meansfor waxing the thread and a trimming mechanism for trimming the sewnseam.

The present application is a division of applicants co-pendingapplication Serial #386,551 filed October'l6, 1953 for Shoe Mach nes.

it is a principal object of the invention to improve the constructionand operation of the inseam sewing mechanism of the machine withparticular reference to the deyices for guiding and waxing the threadWith this and other objects in view as may hereinafter appear a featureof the invention'cons'ists in the means provided for guiding the threadthrough the machine whereby the thread passing from the take-up ofthe machine is guided to the work in a more direct path in which protection isafforded to the thread during its passage through the machinesubstantially to thelooper To this end the thread is arranged to bedrawnfrom an idler roller in the machine head through an eye,

axial bore in thelooper shaft, and through the looper eye. The pathfollowed is substantially a straight line. 'Ihe arrangement shown is ofparticular value in a machine of the type described having a trimmingmechanism for trimming the sewn seam to protect the thread, and

particularly the waxed portion thereof, from direct contact with the airstream produced by the chip exhaust blower, and also to protect thethread from possible contact with the rotary trimming knife.

A feature of the invention consists in the provision of a novel andimproved thread waxing device which comprisesla container for coldliquid wax, and a conduit system including a return conduit to the waxpot through which wax is continuously forced by a feed pump, in order toprevent clogging of the conduits and to maintain the wax in usablecondition. A plunger type :of pump is employed which imparts successivesurges to the through the conduits, timed to cause the pressure to be ata maximumd'uring that portion'of the Isewing cycle when the thread ismoving.

Further in accordance with the invention, the thread waxing device ofthe illustrated construction is arranged .to apply the wax to the threadas it passes through the eye of the looper 'just prior to the time whenthe .wax hardens, thereby substantially improving the quality ot-thestitching produced in the machine.

United States Patent 0 ice v The several features of the inventionconsist also the devices, combinations and arrangement ofparts"hereinafter described and claimed which, together with the advantagesto be obtained thereby, will be readily understood by one skilled in theart from the followingdescription, taken in connection with theaccompanying drawings in which Fig. 1 is a detail view of the sewingmechanism of the machine looking from the right and partly in section,to illustrate particularly the construction and operation of themechanism for supplying wax to the thread;

Fig. 2 is a detail view" in left side elevation, partly in section,illustrating particularly the supportingand actuating connections forthe looper, the thread finger, and needle, and including the conduit forsupplying cold wax to the-thread at' the tip of the looper;

Fig. 3 is an enlarged detail sectional view showing the tip of thelooper and the means for waxing the thread mounted therein, and 4 Fig. 4is a detail sectional view taken on a line of Fig. 2.

Referring to the drawings, the machine disclosed as embodying in apreferred form the several features of the invention is a chainstitchshoe sewing mechanism having a curved hook needle 129 movable in theline pf feed, an oscillatory looper 122 and a thread finger" 124 whichis movable in a direction substantially parallel ito the line of feedand away from the trimming knife of the machine, these parts beinglocated entirely at that side of the sewing point away from thecompleted stitches of the seam to cooperate with a rotary tubular knife,

which is of relatively large size with its axis parallel "to the line offeed and with the cutting edge of the knife passing transversely acrossthe sewn inseam. The illu srated machine is provided with a chip exhaustdevice which includes a chip collector. and exhaust conduit'generallyindicated at 526 in Figs. 1 and 2, which is adapted to collect and toremove chips taken off by the rotary mseaming trimming knife.

The shoe, mounted on a last and preferably carried on an automaticsupport, is guide'din position with relation to the several operatingdevices during the transfer'of the operation about the sole marginoftheshoe by means of a channel guide 138 which is arranged to ride in astitch'receiving channel and support the shoe agimst the needle, and thecooperating welt guide designated at 140 which yieldingly engagesagainst and iis periodically locked against the outer edge of the shoe.The mechanism for supporting and actuating the sewng mstrumentalities ofthe illustrated machine, while in general similar to corresponding partsillustrated'in United States patent to Merrill Patent No. 2 529 095dated November 7, 1950, will be briefly desciibed as follows inconnection with Figs. 1 and 2 of the drawings. I The curved hook needle12% together with its supportir g segment 554 is carried on anoscillatory feed lever 5:5 having back and forth movement in the line offeed. :ihe needle feed lever is formed with a sleeve hub which s mountedon a vertical pivot shaft 558 and a rearwardly extending cam lever arm569 which carries a follower roller 562 for engagement with a peripheralfeedcain track in a cam disk on the sewing camshaft of the machine. Theneedle 12% is mounted on a segmentalsupport 564 and is fuither supportedagainst lateral strains by means of a needle guide 566. Oscillatorymovements ineans of connections comprising a link 56% connected l 'sensr s rrt e in haf 5 .Ih l nn 5701a at one end to the' segment554 and atitsother end to a lever freely mounted to rotate on an axis providedbyloop drawing stroke. the illustrated machine comprises a wax pot 700which is connected by a link 574 to a needle cam actuated lever 575(Fig. 1).

The looper 122 is supported on a rock shaft 576 to on a small radiusabout'an axis inclined forwardly from the vertical and substantially inline with the end of the needle when in the needle threading position.The looper rock shaft 576 is supported for rotational movement in a borein a forwardly extending bracket 578 Qc'arried on the nose of the sewinghead. The looper rock shaft 576 is carried by and is fixedly securedwith a sleeve *shaft 577 mounted to turn on ball bearings in said bore.

A clamping nut 580 is provided for fastening together thesleeve shaft577 and looper rock shaft 576. The

sleeve shaft 577 is provided adjacent its lower end with a worm gear 582which meshes with'a worm 584 on a rearwardlyextending driving sleeve 586externallysupported in a bearing formed on the bracket 578.

H A tapered pinion 588 formed on the rearward end of v the drivingsleeve 586 meshes with a correspondingly tapered gear segment 590 on onearm of the bell crank -1ever 592 supported to turn on the sleeve hub onthe needle actuating lever 570. of the bell crank 592 is connected by alink 594 with one An upwardly extending arm arm of a cam actuated lever596. The'thread finger 124 is secured to the forward'end ofa drive shaft598 which is mounted within the sleeve drive shaft, 586. At its rear endthe shaft 598 is formed with a beveled gear segment 600 meshing with abeveled gearsegment 602 which constitutes one arm of a bell crank 603mounted to turn on.the sleeve hub of the needle actuating lever 570. Theother arm of the bell j crank 603 is connected by a link 604 with a camactuated lever indicated at 606. Y

.The thread handling devices of the machine include additionally athread take-up and a thread tensioning device. The thread take-upcomprises a take-up lever 610 (see ,Fig. 1) which is supportedintermediate its length to turn on a pivot 612. At its forward end lever610 carries a take-up roller 614, and at its rear end is provided with acam follower roller 616.

The thread, drawn from a suitable source of supply,

1 passes around a tension wheel 618 of conventional design, under aroller 620, over a take-up roller 614, around rollers 622 and 624, andthence downwardly to the looper 122. V

In the illustrated machine the thread is arranged'to stantiallystraight-line extension of the perforation through the work. Intheillustrated machine, thisarrangement "for guiding the thread has thefurther advantage that 'the thread passing through the bore in thelooper rock shaft 576 is protected from the air stream created by thechip exhaust blower until it reaches a point close to the looper eye.

tween the chamber 706 in block 7 08 and an inlet port 716 in the underside of the wax pot 700 serves as a return channel for wax which thus ispermitted to circulate from the outlet designated at 702 through conduit704 into the chamber 706 and thence through conduit 714 and inlet port716 back to the wax pot.

Wax isforced through the connections above-described by means of a pumpcomprising a cylindrical chamber 718 (Fig. 1) provided 'by an upwardextension of the cup 702 and a piston 720 supported to slide in thechamber. The piston 720 is connected by a connecting rod 722 with onearm of a lever 724, the other arm of which is connected to an eccentriclink 726 and strap .728 which is'mounted on an eccentric 730 on the camsewing shaft 196 of the sewingmachine. Wax is drawn into the pumpchamber during the upward movement of the piston 720 through a port 732past a check valve comprising a spring-seated ball 734, and isthereafter forced outwardly through the outlet 702 and conduit 704through a second check valve provided by a ball 736 spring seated in thecup 702. Excess wax forced through the chamber 706 is returned throughconduit 714 and inlet 716 past a check valve provided by anotherspring-seated ball element' 738." The pulsations provided by theeccentric pump above described are preferably timed with relation to thesewing cycle to increase the wax pressure when the threadis running,beginning as the looping is started and ending with the needle in itsfully retracted position.

The circulatory system for supplyingwax to'the machine as'abovedescribed has the particular advantage that any tendency of the wax toclog or harden in the relatively small conduits is overcomeand the waxin the wax pot 700 is at all times sufliciently stlrred and agitated toprevent deterioration.

" Further in accordance with the invention, the wax .supplied by thepressure system above described is adapted to be applied to the threadat the point where it passes through the nose of the looper so that thewaxing of the'thread takes place at the last possible moment before thethread is drawn into the work. To this end the looper rock, shaft 576 isformed with a conduit which extends downwardly along the length of thelooper rock shaft 576 eccentric to the axis and terminates at its lowerendin a wax applying chamber 742 extending substantially, the length ofthe looper nose. The conduit 740 may be. formed by cutting a slotlongitudinally in the periphery of the looper rock shaft 576, the slotbeing closed by a cover member 743 as shown in Figs. 2 and s i per rings744 and 746 at the upper and lower ends of. this chamber-serve toconfine the wax within the chamber while permitting passage'of thethread therethrough. The conduit 740 opens'at its upper end into thechamber'706 formed in the bracket 708.

Further in accordance with the invention a novel and improved threadwaxing device is provided which is particularly adapted for applyingcold wax to the thread just'prior to the point at which the newly waxedthread will first be drawn into the work by the needle upon its Thethread waxing mechanism of mounted on the side of the'machine and servesas a reservoir for a supply of cold liquid wax. There is provided in thebottom of the wax pot an outlet in the form V of a depending cup 702(Fig. 1) to which is connected a conduit or tube 704 through whichliquid wax is conveyed to a chamber 706 (Fig. 2) formed within a block708 fitted over the upper end of the rotatable looper supporting rockshaft 576. The chamber 706 is closed 'atits upper and lower ends bybearing washers 710, 712

'--Withthis construction and arrangement of the thread waxing device, acontinuously available supply of wax is providedlwhich, because of thecirculatory system above described, is maintained at all times in afresh and usable condition.- The construction shown has the specificadvantage that the wax and the thread are both brought to a point closeto the work without being ex- 7 posed to the air stream created by thechip blower. The applying of the wax to'the thread as it passes throughthe looper nose has been found to be of substantial advantage in thatthe wax on the thread does not have an fopportunity to dry off or setbefore the stitch is formed and finally set in the work. a I

The invention having been described, what is claimed 1. In an inseamshoe sewing machine adapted for sewing'af chain stitch, the'combinationof a hook needle, a

' looper provided with a thread eye movable to position a bite of threadin the needle hook when projected through the work, a thread fingercooperating the looper to engage said bite of thread in the needle hook,

enemas a thread take-up for drawing the thread passing through thelooper to the needle and work, and a waxing device for the threadcomprising a wax pot, an applicator located at the looper thread eye forsupplying wax to the thread, and a closed conduit extending from the potto said applicator for supplying wax to the thread only at said looperthread eye.

2. In a chain stitch wax thread shoe sewing machine, the combinationwith stitch form ng devices including a hook needle and a needlethreading looper, and devices guiding the thread from the supply to saidlooper while unwaxed, of a waxing device comprising a wax applicator onthe looper for applying wax to a portion of said unwaxed thread passingthrough the looper, and means for supplying wax under pressure to saidapplicator.

3. In a chain stitch wax thread shoe sewing machine, the combinationwith stitch forming devices including a curved hook needle and a needlethreading looper formed with a thread eye through which the threadpasses, of a thread waxing device comprising means on the loopersupplying wax at the thread eye and applying said wax to the portion ofsaid thread passing through said thread eye, said means including aconduit for conducting wax to said thread waxing device.

4. In a chain stitch wax thread shoe sewing machine, the combinationwith stitch forming devices including a curved hook needle and a needlethreading looper formed with a thread eye through which the threadpasses, of a thread waxing device which comprises a wax pot for thestorage of liquid wax, wax conveying conduits extending between the potand the looper eye, and a wax receiving chamber in the looper eyeconnected with said conduits and apertured for guiding the threadthrough said chamber for the application of the wax to the thread.

5. In a wax thread shoe sewing machine having stitch forming devicesincluding a hooked needle and a needle threading device, the combinationof a thread waxing device which comprises a wax pot for the storage ofliquid wax, a circulatory conduit system through which wax circulatesfrom the wax pot and is returned thereto, means for maintaining a flowof wax through said system, a wax applicator on the needle threadingdevice, and a conduit between the circulatory conduit system and theapplicator through which wax is applied to the applicator.

6. In a wax thread shoe sewing machine having 45 stitch forming devicesincluding a curved hooked needle, and a looper assembly comprising alooper rock shaft, an offset looper arm on the rock shaft, and a loopereye formed in the looper arm, the combination of a thread waxing devicewhich comprises a wax pot for the storage of cold liquid wax, acirculatory conduit system through which wax circulates from the waxpotand is returned thereto, means for maintaining a flow of wax throughsaid system, a wax applicator in the looper eye, and a conduit formed insaid rock shaft connected between said circulatory conduit system andapplicator and through which wax is supplied to said applicator.

7. In a wax thread shoe sewing machine having stitch forming devicesincluding a curved hook needle, a looper assembly comprising a hollowlooper rock shaft disposed substantially in line with the tip of theneedle when through the work, an offset looper arm on the rock shaft,and a looper eye formed in the looper arm, means for guiding the feedingthread through said hollow rock shaft to the looper eye, a thread waxingdevice which comprises a wax pot for the storage of cold liquid wax, acirculatory conduit system through which wax circulates from the wax potand is returned thereto, a reciprocating pump operable for periodicallyforcing wax through said circulatory conduit system, a wax applicator inthe looper eye, and a conduit formed in said rock shaft connectedbetween said circulatory conduit system and said wax applicator throughwhich wax is applied to said applicator.

8. In a shoe machine of which the operating devices include a wax threadinseam sewing mechanism comprising a curved hook needle, a looperassembly having a hollow looper rock shaft disposed substantially inline with the tip of the needle when through the work, an offset needlethreading looper eye with a wax applicator formed therein, and means forguiding the feeding thread through the hollow rock shaft to saidapplicator, an inseam trimming mechanism comprising a rotary tubularinseam trimming knife arranged to cause the knife edge to passtransversely across and to trim that portion of the inseam held by thelast-completed stitches of the seam, and a chip exhaust device includingan exhaust conduit through which chips are drawn off, and meansincluding a separate wax conduit formed in said hollow looper rock shaftfor supplying wax to the applicator.

References Cited in the file of this patent UNITED STATES PATENTS253,157 Campbell Jan. 31, 1882 331,306 Landis Dec. 1, 1885 800,554 DenneSept. 26, 1905 2,529,095 Morrill Nov. 7, 1950

